Iverson Grant L, Büttner Fionn, Caccese Jaclyn B
Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, United States.
Spaulding Research Institute, Spaulding Rehabilitation Hospital, Charlestown, MA, United States.
Front Neurol. 2021 Sep 29;12:727089. doi: 10.3389/fneur.2021.727089. eCollection 2021.
A controversial theory proposes that playing tackle football before the age of 12 causes later in life brain health problems. This theory arose from a small study of 42 retired National Football League (NFL) players, which reported that those who started playing tackle football at a younger age performed worse on selected neuropsychological tests and a word reading test. The authors concluded that these differences were likely due to greater exposure to repetitive neurotrauma during a developmentally sensitive maturational period in their lives. Several subsequent studies of current high school and collegiate contact/collision sports athletes, and former high school, collegiate, and professional tackle football players have not replicated these findings. This narrative review aims to (i) discuss the fundamental concepts, issues, and controversies surrounding existing research on age of first exposure (AFE) to contact/collision sport, and (ii) provide a balanced interpretation, including risk of bias assessment findings, of this body of evidence. Among 21 studies, 11 studies examined former athletes, 8 studies examined current athletes, and 2 studies examined both former and current athletes. Although the literature on whether younger AFE to tackle football is associated with later in life cognitive, neurobehavioral, or mental health problems in former NFL players is mixed, the largest study of retired NFL players ( = 3,506) suggested there was not a significant association between earlier AFE to organized tackle football and worse subjectively experienced cognitive functioning, depression, or anxiety. Furthermore, no published studies of current athletes show a significant association between playing tackle football (or other contact/collision sports) before the age of 12 and cognitive, neurobehavioral, or mental health problems. It is important to note that all studies were judged to be at high overall risk of bias, indicating that more methodologically rigorous research is needed to understand whether there is an association between AFE to contact/collision sports and later in life brain health. The accumulated research to date suggests that earlier AFE to contact/collision sports is not associated with worse cognitive functioning or mental health in (i) current high school athletes, (ii) current collegiate athletes, or (iii) middle-aged men who played high school football. The literature on former NFL players is mixed and does not, at present, clearly support the theory that exposure to tackle football before age 12 is associated with later in life cognitive impairment or mental health problems.
一种有争议的理论认为，12岁之前进行美式橄榄球擒抱式比赛会导致日后出现脑部健康问题。该理论源于一项对42名退役美国国家橄榄球联盟（NFL）球员的小型研究，该研究报告称，那些开始进行美式橄榄球擒抱式比赛年龄较小的球员在特定神经心理学测试和单词阅读测试中的表现较差。作者得出结论，这些差异可能是由于他们在生命中发育敏感的成熟阶段更多地暴露于重复性神经创伤。随后对当前高中和大学接触/碰撞运动运动员以及前高中、大学和职业美式橄榄球擒抱式比赛球员的几项研究并未重复这些发现。这篇叙述性综述旨在（i）讨论围绕首次接触（AFE）接触/碰撞运动的现有研究的基本概念、问题和争议，以及（ii）对这一证据体系进行平衡解读，包括偏倚风险评估结果。在21项研究中，11项研究调查了前运动员，8项研究调查了现役运动员，2项研究同时调查了前运动员和现役运动员。尽管关于较早开始接触美式橄榄球擒抱式比赛是否与前NFL球员日后的认知、神经行为或心理健康问题相关的文献存在分歧，但对退役NFL球员的最大规模研究（n = 3506）表明，较早开始接触有组织的美式橄榄球擒抱式比赛与主观体验到的较差认知功能、抑郁或焦虑之间没有显著关联。此外，目前没有已发表的关于现役运动员的研究表明，12岁之前进行美式橄榄球擒抱式比赛（或其他接触/碰撞运动）与认知、神经行为或心理健康问题之间存在显著关联。需要注意的是，所有研究在总体上都被判定为具有较高的偏倚风险，这表明需要更严格的方法学研究来了解首次接触接触/碰撞运动与日后脑部健康之间是否存在关联。迄今为止积累的研究表明，较早开始接触接触/碰撞运动与（i）当前高中运动员、（ii）当前大学运动员或（iii）曾在高中踢足球的中年男性较差的认知功能或心理健康无关。关于前NFL球员的文献存在分歧，目前并未明确支持12岁之前接触美式橄榄球擒抱式比赛与日后认知障碍或心理健康问题相关的理论。
